53 lines
1.9 KiB
Diff
53 lines
1.9 KiB
Diff
From: Theodore Ts'o <tytso@mit.edu>
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Date: Sun, 8 Jul 2018 19:35:02 -0400
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Subject: ext4: fix false negatives *and* false positives in
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ext4_check_descriptors()
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Origin: https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git/commit?id=44de022c4382541cebdd6de4465d1f4f465ff1dd
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Bug-Debian: https://bugs.debian.org/903838
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Ext4_check_descriptors() was getting called before s_gdb_count was
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initialized. So for file systems w/o the meta_bg feature, allocation
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bitmaps could overlap the block group descriptors and ext4 wouldn't
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notice.
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For file systems with the meta_bg feature enabled, there was a
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fencepost error which would cause the ext4_check_descriptors() to
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incorrectly believe that the block allocation bitmap overlaps with the
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block group descriptor blocks, and it would reject the mount.
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Fix both of these problems.
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Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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Cc: stable@vger.kernel.org
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---
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fs/ext4/super.c | 5 ++---
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1 file changed, 2 insertions(+), 3 deletions(-)
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--- a/fs/ext4/super.c
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+++ b/fs/ext4/super.c
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@@ -2307,7 +2307,7 @@ static int ext4_check_descriptors(struct
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
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ext4_fsblk_t last_block;
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- ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0) + 1;
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+ ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
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ext4_fsblk_t block_bitmap;
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ext4_fsblk_t inode_bitmap;
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ext4_fsblk_t inode_table;
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@@ -4050,14 +4050,13 @@ static int ext4_fill_super(struct super_
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goto failed_mount2;
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}
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}
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+ sbi->s_gdb_count = db_count;
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if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
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ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
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ret = -EFSCORRUPTED;
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goto failed_mount2;
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}
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- sbi->s_gdb_count = db_count;
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-
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timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
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/* Register extent status tree shrinker */
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